#
#  Intel(R) Enclosure LED Utilities
#  Copyright (C) 2009-2019 Intel Corporation.
#
#  This program is free software; you can redistribute it and/or modify it
#  under the terms and conditions of the GNU General Public License,
#  version 2, as published by the Free Software Foundation.
#
#  This program is distributed in the hope it will be useful, but WITHOUT
#  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
#  more details.
#
#  You should have received a copy of the GNU General Public License along with
#  this program; if not, write to the Free Software Foundation, Inc., 
#  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
#
=head1 NAME

ledmon - Intel(R) LED monitor service for storage enclosures.

=head1 SYNOPSIS

B<ledmon> [I<OPTIONS>]

=head1 DESCRIPTION

The ledmon application is a daemon process used to monitor a state of
software RAID devices (md only) or a state of block devices. The state
is visualizing on LEDs associated to each slot in an enclosure or a
drive bay. There are two types of system: 2-LEDs system (Activity LED,
Status LED) and 3-LEDs system (Activity LED, Locate LED, Fail
LED). This application has the highest priority when accessing the
LEDs.

The ledmon application uses SGPIO and SES-2 protocol to control
LEDs. The program implements IBPI patterns of SFF-8489 specification
for SGPIO. Please note some enclosures do not stick close to SFF-8489
specification. It might happen that enclosure processor will accept
IBPI pattern but it will blink LEDs not according to SFF-8489
specification or it has limited number of patterns supported.

LED management (AHCI) and SAF-TE protocols are not supported.

There's no method provided to specify which RAID volume should be monitored
and which not. The ledmon application monitors all RAID devices and visualizes
their state.

The ledmon application has been verified to work with Intel(R) storage
controllers (i.e. Intel(R) AHCI controller and Intel(R) SAS controller).
The application might work with storage controllers of other vendors
(especially SAS/SCSI controllers). However storage controllers of other
vendors have not been tested.

The ledmon application is part of Intel(R) Enclosure LED Utilities. Only
single instance of the application is allowed.

=head1 OPTIONS

=over 8

=item B<-c> or B<--config>=I<path>

Sets a path to local configuration file. If this option is specified the
global configuration file and user configuration file has no effect.

=item B<-l> or B<--log>=I<path>

Sets a path to local log file. If this option is specified the global log
file F</var/log/ledmon.log> is not used.

=item B<-t> or B<--interval>=I<seconds>

Sets time interval between scans of sysfs. The value is given in seconds.
The minimum is 5 seconds the maximum is not specified.

=item B<--quiet> or B<--error> or B<--warning> or B<--info> or B<--debug> or B<--all>

Verbose level - 'quiet' means no logging at all and 'all' means to log
everything. The levels are given in order. If user specifies more then one
verbose option the last option comes into effect. The default level is
'warning'. Verbose level also can be set by B<--log-level>=I<level>.

=item B<--foreground>

Run process foreground instead of a daemon. This option is useful in
systemd service file. Another use case of this option is debugging with
elevated B<--log-level>=I<level>.

=item B<-h> or B<--help>

Prints this text out and exits.

=item B<-v> or B<--version>

Displays version of ledmon and information about the license and exits.

=back

=head1 FILES

=over 8

=item F</var/log/ledmon.log>

Global log file, used by ledmon application. To force logging to user defined
file use I<-l> option switch.

=item F</etc/ledmon.conf>

Global configuration file, shared between ledmon and all ledctl application
instances. Local configuration file can be used by running ledmon with I<-c>
switch.

=back

=head1 LICENSE

Copyright (c) 2009-2017 Intel Corporation.

This program is distributed under the terms of the GNU General Public License
as published by the Free Software Foundation. See the build-in help for details
on the License and the lack of warranty.

=head1 BUGS

The ledmon application does not recognize PFA state (Predicted Failure Analysis),
hence the PFA pattern from SFF-8489 specification is not visualized.

=head1 SEE ALSO

ledctl(8), ledmon.conf(5)

=head1 AUTHOR

This manual page was written by Artur Wojcik <artur.wojcik@intel.com>. It may
be used by others.